Testing instrument for vehicles



Jul 11, 1939. w, HbHND lg 2,165,894

TESTING INSTRUMENT FOR VEHICLES Filed April 6, 1937 Patented July 11,1939 2,165,894

v UNITED STATES i- ATENT OFFICE TESTING INSTRUIJENT FOR VEHICLES WilhelmHiihndorf, Hanover-VValdheim, Germany Application April 6, 1937, SerialNo. 135,343 In Germany March 2, 1937 4 Claims. (Cl. 264---1) The presentinvention relates to an instruvehicle, the supporting plate 1 of theinstrument ment of a device for ascertaining the efiiciency is pivotallyconnected at 8 to the frame Hi and of the brakes of a vehicle by testingthe retardais fixed to a wall of the vehicle by means of tion of avehicles movement during the period screws, rubber suction cups or thelike not shown of braking, or for ascertaining the acceleration in thedrawing, in such a manner, that the 1011- 5 during running. The newinstrument or device gitudinal axes of the vehicle and of the glass isadapted for use on motor cars or the like, and tube l extend. in thesame direction. Then the is characterized principally by a ball,preferably swingable frame is levelled, by means of a water cbnsistingof steel, movably arranged in an inlevel 8 fixed to the frame Hi,adjustment being clined tube, in such a manner, that the movepermittedby the pivot 8. A clamp screw H! on ment of said ball along said tubedue to its kia lever 12 passing through a straight-lined slot neticenergy serves as a measure for the retardais provided in the frame 14 atan angle of about tion or acceleration of the vehicles movement 90 tothe scale 5 serves to fix frame I4 in adduring the braking period orduring the accelerajusted position. The other end of the lever l2 0 tionof the vehicle respectively. is linked at H to the supporting plate I.When The ball preferably is arranged in a tube, the the brakes of thevehicle are applied the ball longitudinal axis of which extends in thesame 2 moves along the inclined tube only if a predirection as thelongitudinal axis of the vehicle determined deceleration rate has beenattained. to be tested, and is inclined to the horizontal. The presetinclination of tube 1 determines the Preferably the tube may be adjustedto vary its actual value of deceleration for which the device soinclination and fixed in an adjusted position in is operative. front ofa scale. The instrument may be used for ascertaining Further essentialfeatures of the invention are the retardation of the vehicle during thebraking stated in the following specification and the period and theacceleration during running re- 5 claims. In testing instrumentsaccording to the spectively, by reversely arranging the tube, that 3;,invention, the inclination of the tube determines is to say, by soarranging the parts that the the inclination of the path traversed bythe ball connecting plate points rearwardly in the direcand thusmeasures the retardation of the vetion of travel.

hicles movement during the braking period or The tube I preferablycontains a damping the acceleration in operation. liquid, air or anotherdamping medium. to

The advantages of the new instrument con- If the instrument is used onlyto ascertain one sist in simplicity of construction, a high degree orseveral average retardations of the vehicles of exactness, low price ofmanufacture, eliminamovement during the braking period, for instancetion of the problem of spring fatigues and the the retardation of 25m./sec. or 32.8 ft./sec. like and of other faults as well as providingan prescribed for the foot brake and the retardainstrument wherein aprescribed retardation tion of 1.5 m./sec. or 19.7 ft./sec. prescribedfor during the braking period may be determined in the hand brake, then,instead of providing 2, advance by varying the inclination of the tubescale, the lower end of the tube may be surand then be ascertained bythe movement of rounded by an opaque casing for such a length, the ballbeyond an opaque casing (not shown) that any appearance of the ballabove this casing or the like, surrounding part of the tube so thatindicates, that the brakes are in order. Preferits free end terminatesat a point along the tube ably the slot provided for the adjustment ofthe which is reached by the ball at the minimum tube in such a structurehas such dimensions value of retardation. only, that when the tubeoccupies the lower po- In the accompanying drawing one construcsition inthe slot, the appearance of the ball betion according to the inventionis shown by way yond the casing of the tube corresponds to a reofexample in side elevation. tardation of 2.5 m./sec. or 32.8 ft./sec.whereas,

A glass tube carrying a movable steel ball when the tube is adjustedinto the upper posi- 2 is arranged in an arm 2a pivotally mounted tion,the appearance of the ball beyond the easin the bearing 3 provided in aframe 14. Arm 2c ing corresponds to a retardation of 1.5 m./sec. 50

may be fixed in any desired inclined position or 19.7 ft./sec.

in front of a scale 5 of the frame It by means If the instrument isfixed to the dash-board of a clamp screw 4 passing through a curved of amotor car, alamp may be provided to illumislot 6 also provided in theframe l4. hate the instrument, so that it may also be read Beforestarting the testing of the brakes of 21. off in the dark.

What I claim is:

1. In an instrument as set forth, a supporting plate, adapted to befixed to a portion of a vehicle, a frame adjustably connected to saidplate having a straight-lined slot, a link pivoted to said supportingplate, a screw carried by said link passing through said slot in saidframe, a tube pivoted to said frame and adapted to be adjusted in aplane parallel to the direction of drive of the vehicle, a ball movablyarranged in said tube for movement therealong to indicate decelerationor acceleration, means for fixing said tube in an adjusted position, andmeans for controlling the inclination of said tube.

2. In an instrument as set forth, a supporting plate adapted to be fixedto a portion of a vehicle, a frame linked to said supporting platehaving a straight-lined slot and a curved slot extending at an angle ofabout 90 to said straightlined slot, a link pivoted to said supportingplate, a screw carried by the free end of said link en-- gaging saidstraight-lined slot, a tube pivoted to said frame, a ball freely movablearranged in said tube for movement therealong to indicate decelerationor acceleration, and a screw carried by the free end of said tubeextending through said curved slot and serving to fix said tube in anadjusted position.

3. In an instrument as set forth, a supporting plate adapted to be fixedto a portion of a vehicle, a frame linked to said supporting platehaving a straight-lined slot and a curved slot extending under an angleof about 90 to said straight-lined slot, a scale provided adjacent tosaid curved slot on said frame, a tube pivoted to said frame and adaptedto be adjusted in a plane parallel to the direction of drive of avehicle, said tube containing a damping medium, a ball freely movable insaid tube for movement therealong to indicate deceleration oracceleration, a screw at the free end of said tube engaging said curvedslot and adapted to fix said tube in a predetermined position, and aWater level connected to said frame.

4. An instrument for measuring acceleration or deceleration comprising asupport adapted to be secured to a rigid portion of a vehicle or thelike, a frame pivotally adjustably mounted upon said support and meansfor locking said frame in a desired position of adjustment upon saidsupport, a tube containing an inertia member pivotally mounted upon saidframe and adapted to be adjusted to an inclined position in a planeparallel to the direction of drive of the vehicle, means for indicatingthe degree of adjustment of said tube and means for locking said tube ata predetermined position of adjustment and level indicating meansmounted on said frame.

W. HoHNDORF.

